Although we got bits and pieces of supersecondary structure, nothing we came up with looked like a complete model. We felt that the conserved histidines, H174, H176, and H187 ought to cluster, perhaps at a metal-binding site, but they did not cluster naturally in any of our models. When we forced clustering, we lost predicted secondary structur. This is try16-opt2, the undertaker-generated model that scores best with cost functions that require clustering the histidines (excluding models derived from robetta).